Li掺杂ZnO纳米棒的导电和发光特性(英文)

利用气相输运方法,在(111)面硅衬底上制备了名义上原子数分数为2%的Li掺杂的ZnO纳米棒(样品A)。作为比较,我们在相同的生长条件下制备了没有任何掺杂的ZnO纳米棒(样品B)。XRD分析测试表明:样品A和样品B中的ZnO纳米棒具有纤锌矿六边形结构,没有其他氧化物,例如Li2O。Hall效应测量表明:样品A导电类型为p型,空穴载流子浓度为6.72×1016cm-3,空穴载流子迁移率为2.46 cm2.V-1.s-1。样品B为n型,电子载流子浓度为7.16×1018cm-3,电子载流子迁移率为4.73 cm2.V-1.s-1。低温光致发光光谱测试表明,样品A和样品B发光峰明显的区别是位于3.351 eV(样品B)和3.364 eV(样品A)处。根据文献报道,在没有掺杂的ZnO中,3.364 eV发光峰源于施主束缚激子发光。通过变温光致发光光谱的测试,证明了在样品A中,位于3.351 eV的发光峰源于受主束缚激子发光,其光学受主能级位于价带顶142meV处。

Electrical and Optical Properties of Li-doped ZnO Nanorods

Li-doped ZnO nanorods was grown on n-Si (111) substrate by chemical vapor deposition. XRD pattern showed that the nanorods are pure wurtzite ZnO of hexagonal crystal structure without any other oxide, such as Li2O. Hall effect experiment under Van der Pauw configuration showed that Li-doped ZnO nanorods behave the p-type conductivity with hole concentration of 6.72×1016 cm-3 and a Hall mobility of 2.46 cm2 ·V-1·s-1. A neutral acceptor- bound exciton emission (A°X) was confirmed by the measurements of temperature-dependent photoluminescence (PL) spectra. The optical acceptor energy level is calculated to be about 142 meV.